Using a PHP iterator to implement a Fibonacci sequence

The Fibonacci sequence is usually done recursively, and of course there are other methods. This is now learning to sell, using a PHP iterator to implement a Fibonacci sequence, with little difficulty, just rewrite the next () method in the class. Comments have been written into the code and are quite well understood. Dingzhou Technology Industry Bureau

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01

/**

02	* @author 简明现代魔法 http://www.nowamagic.net

03

*/

04	classFibonacci implementsIterator {

05	private$previous= 1;

06	private$current= 0;

07	private$key= 0;

08

09	publicfunctioncurrent() {

10	return$this->current;

11

}

12

13	publicfunctionkey() {

14	return$this->key;

15

}

16

17	publicfunctionnext() {

18

// 关键在这里

19	// 将当前值保存到 $newprevious

20	$newprevious= $this->current;

21	// 将上一个值与当前值的和赋给当前值

22	$this->current += $this->previous;

23	// 前一个当前值赋给上一个值

24	$this->previous = $newprevious;

25	$this->key++;

26

}

27

28	publicfunctionrewind() {

29	$this->previous = 1;

30	$this->current = 0;

31	$this->key = 0;

32

}

33

34	publicfunctionvalid() {

35	returntrue;

36

}

37

}

38

39	$seq= newFibonacci;

40

$i= 0;

41	foreach($seq as$f) {

42	echo"$f ";

43	if($i++ === 15) break;

44

}

Program Run Result:

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1	0 1 1 2 3 5 8 13 21 34 55 89 144 233 377 610

Using a PHP iterator to implement a Fibonacci sequence